Method for separating cracked hydrocarbon material



Feb. 28, 1933.

N. E. LOOMIS METHOD FOR SEPARA'IING CRACKED HYDROCARBON MATERIAL Filed OCb. 22, 1927 Patented Feb. 28, 1933 UNITED STATES NATHANIEL E. LooMIs, 0E WEsTEIELD, NEW ."rnitsmr,` AssIeNoRffro sTANDAEDfoIL DEVELOPMENT COMPANY, A coEBoEAmIoN or DELAWARE METHOD EonI SEPAEATING oRAoKEDnYDRocARBoN MATER-111D f Application mea october 22, 1927. fseriai no, 22a-Saai Thisy invention relates Vto an improved method for resolving cracked hydrocarbon material into a series of products.

In one method for cracking petroleum oil to form gasoline, a stream of petroleum oil -is flowed through a zone in which it is heated under pressure to a cracking temperature andl thereafter held in a digesting zone in which further crackingk takes place. Cracked material is withdrawnl in a continuous stream from the digesting zone. My

invention particularly comprehends a method for more efficiently separating the material withdrawn into marketable products.

The drawing is a diagrammatic longitudinal cross section of apparatus in which the preferred embodiment of my method may be carried out.

In operating the same, the cracked material from the digestingzone flows, kwithout substantial loss of heat, through pipe 1 to tar separator 2, in which separation takes place. Tar -separated is continuously withdrawn through pipe 3 and cooler 4 to an accumulator. Vapors pass off from the separator through dome 5 and pipe 6.y In

dome 5 the vapors pass in indirect heat interchanging relationship to oil circulating in ycoil 20, which will be hereinafter more fully described. The vapors then pass through` pipe 6 to coil 7 in the lower portion of fractionating column 8 and are partly condensed simultaneously with the re-boiling of the bottoms in column 8 by heat from the vapors. rIhe mixture of liquid and vapor -in coil 7 flows through pipe 9 into chamber 10. 'Ihe vapors are further condensed by contact with coil 12 and the condensate so produced, together with liquid originally present, flows through pipe 13a to vaccumulator 14. The uncondensed vapors flow through pipe 15 to the intermediate portion of tower 16, in which fractionation takes place. The bottoms from the tower 16 pass through pipe 17 to pump 18, by which they are continuously discharged through pipe 19 to the coil 20. In this coil the bottoms partially condense vapors in dome 5, are heatedy thereby, and thereafter flow through pipe 21 to separator 22, in which vapors produced by the heat eX- change` ,separate from the residuall .liquidi The vapor, flows through .pipe722a` and req enters column 16 atthe base forfurtherfracy tionation, while-the. liquid is continuously withdrawn, and may be returned .tothe feed accumulator l14 through pipe 23,' or diverted throughpipe 24 to. cooler 25 and thence to stor'age.'= "Vaporspassing overhead from column-16, movevin heatexchanger `26' in indirect heat finterchanging: relationshipto the feed stock "passingft'o feed accumulator 14 through pipe 26?, thereby simultaneously preheating the` feed and maintaining proper rectifyingconditionsin column A16.: RefluxV returns to the column 16 through pipe-26b,

Thezstreams ofVv liquid discharging; intov accumulator 14 comprise the total feed stockV for'the' crackingunit and ,mayV be withdrawn for that purposecontinuously or periodically, as desired. .Light ends -in the feed stock may be separated therefrom if desired by the ape" plication of Vheat to the accumulator 14 from any suitable sourcethe1vapors so produced passingfthroughpipe 146 tol chamber10,-or alternatively, directly to column 16 through p1pe`140'. '.'Va-'pors from exchanger 26'fpass rthrough pipe27 tothe intermediate section of the final tower .-8, in whichfffactionation takesplace. vThe bottoms in thistowerxare re-boiled by indirect heat exchange with the 8. is provided by partial condenser 29,the;con densate returning to the column through P11103@ f i 1, u i w This"`condenser is ysupplied with cooling water from any source', the amount thereof being adjusted so that the vapors passing olf through pipe 31-to lcoil 32 'in which they are condensed, have an end point of about 360o F. and consist of light naphtha. The bottoms from column 8 may be withdrawn through pipe 33 and cooler 34 or alternatively may be diverted to accumulator 14 thru pipe 33a. By control of the' amount of bot- `material flowing in coil-7. V Reflux to tower .l

toms from the intermediate column passing oil fraction are vaporized and separated therefrom, the product Withdrawn through cooler 25 consisting essentially of gas oil.

The vapors passing overhead from column 16 contain substantially all the fractions Within the gasoline range together with hydrocarbons intermediate gasoline and gas oil such as those present in kerosene. The control supplied by partial condenser 29 further converts these vapors into a light naphtha overhead, which is nally condensed and discharged from cooler 82 and a bottom ofy heavy naphtha and kerosene which is finally cooled and delivered from cooler 34 or returned for further cracking via line 33a. The tar Withdrawn from separato-r 2 contains sufficient condensate as a result of. the circulation of liquidin pipe 20 to impart the necessary iuidity Jfor convenient handling.

t Will be understood that 'the apparatus shown is an illustration and not a limitation and that my method may, be carried out in various forms of apparatus. ,Various alternative procedures may be adopted Within the scope of the appendedclaimain` Which it is my l,intention to claim broadly all novelty inherent in my invention.-

1An improved process for separating mixturesy of hydrocarbons into aseries of valuable condensates, comprising separating vapors from` tarry materials, .passing the vapors in indirect heat exchange with condensate from a. later stage of the operation, passing remaining vapors in indirect heat exchange with a second condensate formed in a later stage of the operation, whereby a portion of the vapors is condensed and the said second.` condensate is reboiled, passing remaining vapors into a rectifying zone in Which they are in part condensed to form the condensate Which is in indirect heat eX- change With the vapors first separated Vfrom thetarry `material, and recovering a final Vapor product from the system.

2.y Method according to claim 1, in which l the vapors from the rectification stage are passed into the stage in which the second con'dens'ateis'` collected and reboiled.

o NATHANIEL E. LooMIs. 

